Double glazed window



May,28, 1940, E. H. HAux u DOUBLE 'GLAZEDy WINDOW Filed May i5. 1937 INVENTOR.' fine-APH H/w/A/ Patented May 1940 UNITED STATES 2,202,694 y DOUBLE GLAzED WINDOW Elmer H. Haux, Tarentum, Pa., assignor to Pitt-sbur'gh Plate Glass Company, Allegheny County, l Pa., a corporation, o! APennsylva'sni'a Application May 15, 1937, Serial No. 142,796 2 Claims. .V20-56.5)

'I'he -invention relates todouble glazed windows which ordinarily consist of two glass sheets or.

plates with a spacer between the'edges of the sheet which. also'acts to seal oli' the space between the sheets from the atmosphere. The windows may be-used iii/"buildings or cars or in refrigerators and the present improvement is applicable in eitherv relation, .the cold side ina building being the outer onef, and in a refrigerator lthe inner one. One of the difficulties encountered with double glazed windows is the formation of condensation on the innerfface of the sheet on the cold side of the window, which obscures the window and results in staining, due to 'the'placing in solution oi' the alkali dustwhich accumulates toa greater or less degree ori-the faces of glass sheets'not accessible for cleaning. It has been proposed heretofore to avoid thisy diiliculty by placing de- 'hydrating materials in communication with the space between the glass sheets and by making the spacer at the edges 'of the sheets as resistant as possible to the passage of moisture-laden air, but

' these expedients are only partially effective, as

the dehydrators become exhausted and no practical sealing and spacing means has, as yet, been devised, which will y"prevent the infiltration of moisture-laden air therethrough.

It has also beenpro'posed to overcome the dimculty bymaintaining the space between the glass sheets `in communication with the atmosphere. on the cold side of the window.` This is eective,

since the air on the cold side oi the window has a relatively low moisture content incident to its temperature and with a passage which 'permits of the circulation of such'- cold low-humidity air to the space between the vglass sheets, there is no more tendency yto condensation on the inner faces lof the glass sheets than on their outer faces. The

expedient has, however,l the drawback that the passage to the space between the sheets permits the inltration of cold air, thus reducing the in-k sulating value of. the glazing unit, and dust may becarried in with the air despite th use of illters of wool or the like for guarding against.

Water may also be introduced through the passage in a driving rain or in washing.

'I'hev present invention is. designed to obviate the objections :incident to the'us'e of dehydrators, and incident -to the use oi' circulating passages. Briefly stated, this is accomplished by the use oi' a communication or passagev leading from the space between the glass sheets to the atmosphere on the cold side of the window, in which a seal is provided oi' such character that it will prevent the passage of water as a liquider of dust-laden air, but-.which is readily permeable by water vapor. This is preferably accomplished by th'e use in the passage of a thin sheet or layer of ellulose acetate or other gas permeable material, such as cellulose ethers, synthetic resins, un- '5. glazed clay'or the like which will seal against water, -but are readily permeable by gases. Any leakage of moisture-laden air to the space between the 'glass sheets from the warm side of the unit, tending to increase the vapor pressure in 101 the unit, will be taken care of by the more rapid release of vapor pressure through the gas permeable seal to the atmosphere on the cold side of the window, so that the vapor pressure of the air in the insulating space will be maintained at 15 the same relatively low point as that of the at- .mosphere on the cold side of the window. There is thusA 1) no condensation inside the unit with resultant possible staining of the glass, (2) no loss in insulationincident to the application of w thev expedient, and (3) no possibility of dust or water entering the unit. Certain embodiments of the invention are illustrated in the accompanying drawing, wherein: J

Figure 1 is a side elevation-of a car Window w.

equipped with the invention. Fig. 2 isa section on the line II-II of Fig. 1. Fig. 3vis an enlarged section through the end ofthe plug employed.

And Fig. 4 is a section through a modication.

Referring to the drawing, 5 and 6 are glass por.

.sheets with aninsulating space 'I therebetween;

8 is the frame of the window, and 9 is a spacer of insulating material, such as rubber having intgral. therewith channel portions in which the edges of the glass sheets are seated.

Secured to the corner of the frame is a casting I0 having a threaded recess carrying the hollow metal plug I I. A pair of passages (I2 only one of which is shown) lead' from the inner end of the threaded recess to rubber sleeves I3 mounted in l recesses in the inner face of the casting. A pair. of metalvtubes It having heads I5 ttingiinto the rubber sleeves extend through the spacer to the space .1.' .Passages are thus provided from the space 'l to the space I6 at theend of the threaded recess. v

The plug II is made tight by a rubber gasket Il and has the inner end provided with perforations I8, as indicated in Fig. 3. The plug is o illled with a body of glass wool I8, and its outer end is closed withk a screw cap I9 which serves also tohold in place on the plug a rotatable sleeve 2li. The sleeve and side wall of the plug are provided with a pair of periorations, as indiu cated at 2|, which are in registration, as shown,

-when the sleeve is in one position of rotation.

. The inner end of the plug is provided with a layer 22 (Fig. 2) of gas permeable material, such as cellulose acetate, preferably unplasticized, which forms a seal against the passage of water and dust between the interior of the plug and the insulating space 1. The glass wool -I 8 guards the layer of cellulose acetate against the direct impact of any water or dirt passing into the plug through the openings at 2|. Any/ con densation forming in the plug will drain out through the openings, as they are located on the lower side of the plug. Since there is no chance of condensation within the glazing units during summer, the lsleeve 20 may be turned during such period, so as to close the opening'l through the Wall of the plug.

It will be seen that the construction described provides a communication from the insulating space 1 to the atmosphere which is interrupted completely against the passage of water, air and -dust by the cellulose acetate or other equivalent layer 22, and it will be understood that this communication is to .the cold., side of the window, namely, to the outer side-in buildings and the like, and to the inner side-in refrigerators. As this layer is readily permeable by water vapor, the vapor pressure in the unit will be equalized with respect to that of the atmos- Y phere with which it communicates. As a result, any vapor pressure which builds up in the space 1 incident to the infiltration of moisture-laden air through the spacerl 9 from the' warrn side of the unit will be released. As the spacer 9 is made of material which will be most resistant to the passage of water vapor, and the layer 22 is of material which readily permits the passage of such vapor, the release of any vapor pressure which tends to accumulate will be rapid enough to permit the maintenance of a humidity in the space 1 approximately that of the atmosphere on the cold side of the unit. The rapidity of vapor transmission through the layer 22 depends on the composition, area and thickness, and these factors may be readily adjusted to give the de` sired rapidity of equalization, as even a layer of rubber may be used if itl is made sufficientlyv thin. The insulating space 1 is completely guarded against access of dirt or water, andv under extreme differences in temperature conditions on opposite sides of the unit, no condensation occurs on the inner. surface of the glass sheet 6 which is the one subject to this diiculty in previous constructions. dersto'od that the invention is equally applicable to triple glazing and that the term double glazed window is generic to windows having two or more panes.

The invention is capable of embodiment in a It wi11- be unsealing means for the passage leading to the` cold side of the window is located in the edge of the sash, instead of in a plug extending from the side thereof as heretofore described. In this structure, 23 is the car frame carrying the metal sash frame made up ofthe parts 24, 25 and 26, similar to that of the Fox and Stroud Patent No. 2,034,856, the sash being cushioned and held in place in the car frame by the rubber strip members 21 and 28. A tube 29 leads fromthe space between the panes 3| and 32 and terminates in a recess 33 of circular cross section at the edge of the sash. 'This recess opens into a Slot 34 which communicates through a passage 35 with a slot 36. Holes 31 lead into the slot 36 from the atmosphere on the outer side of the window. A communication is thus provided from the outer atmosphereto the insulating space 30 between the panes of glass. The recess 33 carries a pair of perforated metal discs 38 and 39- yieldingly held in place'frictionally, and between these discs is a body 40 of mineral woolor similar material. covered with a layer 4| material, such as the cellulose acetate layer 22 'I'he face oi the disc 39 is.

of a gas-permeable of Fig. 3; and this functions/in the same manner as the layer 22,v forming a 'seal against the passage of water or dirt.' butl permitting the 3 equalization ofthe vapor pressure inthe space 30 with that of the outer atmosphere.

What IY claimisz 1. In a double glazed window construction which includes asash having a passage therein opening to the atmosphere and leading theref from tothe space between the panes of the window, a lter in the passage comprising a foraminous support ex nding across the passage, a layer of solid, nonbrous material back of the member which is a positive seal against water' as a liquid and against dust but which is readily permeable by water vapor, and a body of fibrous screening material in the of 'said layer of material.

2. In a double glazed window construction t of said layer of material. ELMER H.A HAUX.

passage back 

